CDL Hazardous Materials Endorsement (HME)Loading and Unloading Hazardous MaterialsHard
A driver is transporting a load that includes both Class 4.3 (Dangerous When Wet) materials and Class 2.1 (Flammable Gas) cylinders. Which of the following segregation requirements applies?
- AThey must be loaded in separate compartments.
- BThey are prohibited from being loaded on the same transport vehicle.
- CThey must be separated by at least 3 feet.
- DThey can be loaded together if properly secured and braced.
Show answer & explanationAnswer & explanation
Correct answer: B. They are prohibited from being loaded on the same transport vehicle.
Class 4.3 (Dangerous When Wet) materials react with water to produce flammable gases. Class 2.1 (Flammable Gas) is, by definition, flammable. Loading these two classes together on the same transport vehicle is prohibited because the flammable gas produced by the Class 4.3 reacting with water could easily be ignited by the Class 2.1, leading to a severe incident.
Why the other options are wrong
- A. Separate compartments are insufficient; the prohibition is for the entire vehicle.
- C. A 3-foot separation is not applicable here; the classes are entirely incompatible on the same vehicle.
- D. Loading them together, even if secured, is extremely dangerous and strictly prohibited.
Segregation: Dangerous When Wet & Flammable Gas
Class 4.3 (Dangerous When Wet) and Class 2.1 (Flammable Gas) are incompatible and prohibited from transport on the same vehicle.
- Class 4.3 reacts with water to produce flammable gas.
- Class 2.1 is flammable gas.
- Prohibited on same transport vehicle.
Memory trick: Dangerous when wet plus flammable gas equals a 'no-go' vehicle.